/*
 * @Author: hucc
 * @Date: 2021-10-04 17:54:30
 * @LastEditors: hucc
 * @LastEditTime: 2021-10-04 17:58:18
 * @Description: 
 */
let iterator = 'hello' [Symbol.iterator]()
console.log(iterator); //Object [String Iterator] {}
console.log(iterator.next()); //{ value: 'h', done: false }
console.log(iterator.next()); //{ value: 'e', done: false }
console.log(iterator.next()); //{ value: 'l', done: false }
console.log(iterator.next()); //{ value: 'l', done: false }
console.log(iterator.next()); //{ value: 'o', done: false }

console.log(String.prototype[Symbol.iterator] === 'helle' [Symbol.iterator]); //true

String.prototype = {
    [Symbol.iterator]: function() {

    }
}